Pumping apparatus as well as a diffusor for a pumping apparatus

ABSTRACT

Disclosed are a diffuser and a pump including a feed column extending around a diffusor axis of the pump and having a rotor housing which is arranged between an intake and a diffusor arranged in a diffusor section. During operation, fluid is sucked by the pump rotor via the intake, and is discharged from the feed column via the diffusor section, the feed tube and the outlet stub. The diffusor includes an inlet section arranged between an outlet section and the pump rotor, wherein a first part section adjacent to the inlet section is formed at the outlet section, the first part section is inclined with respect to the diffusor axis at a first angle (α). A second part section adjoining the first part section is inclined with respect to the diffusor axis at a second angle (β) different from the first outlet angle (α).

The invention relates to a pumping apparatus, in particular to a vertical pump, as well as to a diffusor for a pumping apparatus, in particular for a vertical pump, in accordance with the preamble of the independent claims 1 and 10.

Vertical pumps, in particular large vertical pumps have been used successfully in a plurality of applications for a very long time in the prior art. Large pumps for specific applications are not infrequently manufactured in accordance with the specifications of the users and/or are matched in detail to specific requirements.

Important fields of application for the use of vertical pumps in practice are, amongst other things, cooling towers, applications in cooling water systems, for the drainage of waste water pools, or overflow basins for the prevention of flooding, or vertical pumps are also successfully used for the drainage of large areas of land. Vertical pumps are also widely used in the supply of water, in particular in the supply of drinking water, or as main pumps or as auxiliary pumps in open or closed systems. Other applications are fire-fighting in the off-shore area, for example on drilling rigs, to only mention a few fields of application by way of example. Moreover, a whole series of further applications for vertical pumps are well known to the person of ordinary skill in the art. In this respect the pumps can be fixedly installed in a certain plant in dependence on the application or, however, can also be exchangeably installed or installed in a height adjustable manner, whereby a high flexibility is achieved, for example, in that the vertical position of the pump can be matched to different water levels or to different changing circumstances.

Vertical pumps are thus indeed not only, but typically always used when a large amount of a fluid, not only, but generally water, should be pumped at comparatively low pressures over relatively small differences in height from a lower level to a higher level per unit of time or, also, for only overcoming the pressure-loss in the system. For example, from the ocean, a river, a lake or from a cooling basin, a tank or from a liquid sump or a water sump.

In this respect one stage or multi-stage vertical pumps are used, this means pumps having one or more pump rotors arranged in series, the use of which is determined by the respective specific application.

In this connection the vertical pump is typically immersed into the liquid reservoir to be pumped, so that at least the intake or suction bell with the adjoining pump rotor is immersed into the medium to be pumped, so that the pump is directly ready for operation.

Also when the application of vertical pumps is not generally limited to large feed amounts and the overcoming of comparatively small differences in height, large vertical pumps are, in particular used precisely then when very large amounts of a fluid must be conveyed over comparatively small differences in height per unit time. In this connection typical operating parameters, for example, lie at 1,000 m³ up to 80,000 m³ per hour performance or capacity, which achieve typical feed heights of 1 m-40 m. The conveyed medium is frequently water. In this connection the aforementioned value ranges, are to be understood only by way of example and can be exceeded or undercut in dependence on the application, like the person of ordinary skill in the art knows.

For a better understanding of the present invention the structure and the functional principle of a vertical pump known from the state of the art should now be described in the following with reference to FIG. 1 a and/or FIG. 1 b which vertical pump is improved by the present invention.

At this point it should be noted that reference numerals which relate to features of pumps or pump components known from the state of the art are provided with an inverted comma in the framework of this application, as is the case for the examples known from the state of the art in accordance with FIG. 1 a and/or FIG. 1 b. At the same time reference numerals which refer to features of embodiments in accordance with the invention do not carry an inverted comma, as is the case for the exemplary embodiments in accordance with FIG. 2 a and/or FIG. 2 b.

FIG. 1 a shows a vertical pump 1′ well known from the state of the art having a diffusor 5′, wherein the FIG. 1 b shows the diffusor 5′ of FIG. 1 a in a slightly more detailed illustration for a better understanding.

The vertical pump 1′ known from the state of the art in accordance with FIG. 1 a and/or FIG. 1 b includes a feed column 2′ extending about a diffusor axis A′ of the vertical pump 1′ and having a rotor housing 3′, which is arranged between an intake 20′ and the diffusor 5′ provided in a diffusor section 4′. A feed tube 6′ having an outlet stub 21′ adjoins at the diffusor section 4′. In this connection a pump rotor 7′ is arranged in the rotor housing 3′ such that, in the operating state, a fluid F′ to be conveyed by the pump rotor 7′ can be sucked via the intake 20′ and can be discharged again via the diffusor section 4′, the feed tube 6′ and via the outlet stub 21′ from the feed column 2′ of the vertical pump 1′. In this connection the diffusor 5′ itself includes an inlet section 51′ arranged between an outlet section 52′ of the diffusor 5′ and the pump rotor 7′ in a manner known per se, wherein the outlet section 52′ is configured as a part section 521′ adjoining the inlet section 51′. In this respect the part section 521′ is inclined at an outlet angle α₁′ with respect to the diffusor axis A′ in the direction of the feed tube 6′, with the outlet angle α₁′ frequently not being constant in practice over the overall part section 521′, but also variable so that the outer shape of the part section 521′ does not necessarily, as is the case for the example of FIG. 1 a and/or of FIG. 1 b, have to be designed in the form of a straight conical section or a truncated cone, but can also have a surface curved with respect to the diffusor axis A′.

In this connection the pump rotor 7′ is driven by motor M′ via a drive shaft 8′. The drive shaft 8′ is journalled in bearings 10′ adjustable with respect to the diffusor axis A′ within the diffusor 5′, which does not rotate with the pump rotor 7′, but is statically connected to an inner wall of the diffusor section 4′ by means of attachment means 9′, for example, by means of diffusor vanes.

As can be seen, in particular from the detailed illustration in accordance with FIG. 1 b significant turbulence T′ is present in the fluid F′ following the exit from the diffusor 5′, whereby, as will be explained in the following in more detail, a non-considerable amount of feed energy is lost.

An essential component of a vertical pump, for example, of the vertical pump in accordance with FIG. 1 a and/or FIG. 1 b is thus the diffusor which adjoins the pump rotor in the pump direction as mentioned.

As is well known to the person of ordinary skill in the art the diffusor is a component, which not only in the case of pumps but also in numerous other technical applications serves the purpose of slowing down a liquid flow, whereby flow energy, thus ultimately the kinetic energy of the liquid is converted into pressure energy and the pressure is therefore increased. Therefore, a diffusor is the counter-piece to a nozzle which increases the kinetic energy of the fluid with respect to its manner of operation. The additional pressure gain obtained by the diffusor, which in practice can generally lie in the range of up to 10% of the overall pressure or which can even lie higher in individual cases, can then be used to achieve a higher height difference, i.e. a larger pump head, than without a diffusor.

The transfer of kinetic energy into pressure energy is, amongst other things, achieved in this connection in that fluid flowing away from the pump rotor can be additionally suitably guided, for example, by means of corresponding guide vanes, whereby turbulence and eddies in the fluid can be suppressed to a certain degree which consume a certain part of the flow energy of the flowing fluid by means of internal friction i.e. would ultimately be transferred into heat, so that this energy loss would no longer be available as pressure energy and which finally has the effect that a smaller pump height is achieved and/or more drive energy has to be invested into the pump in order to achieve the desired pump head.

Also when the diffusors so far known from the state of the art satisfy the aforementioned object of energy transfer into pressure energy more or less successfully, it has been shown that a considerable need for improvement still exists with respect to the efficiency of the diffusors. This means that also when the so far known diffusors already make a significant contribution with regard to the energy efficiency of the vertical pump, this still does not seem to be sufficient, in particular with regard to the ever increasing costs of energy.

For this reason it is the object of the invention to provide an improved diffusor and/or pumping apparatus, in particular a vertical pump having an improved diffusor, by means of which a larger portion of pressure energy can be regained from the fluid conveyed by the rotor, so that finally the energy efficiency is increased as a whole and a larger feed height is achieved than for a known diffusor for the same drive energy introduced into the pump, or alternatively that the overall energy consumption of the pump can be reduced for the same feed height.

The subject matter of the invention satisfying this object is satisfied by the features of the independent claims 1 and 10.

The dependent claims relate to particularly advantageous embodiments of the invention.

The invention therefore relates to a pumping apparatus including a feed column having a rotor housing extending about a diffusor axis of the pumping apparatus, with the rotor housing being arranged between an intake and a diffusor provided in a diffusor section, as well as including a feed tube with an outlet stub adjoining at the diffusor section. In this connection, a pump rotor is arranged in the rotor housing such that, in the operating state, a fluid to be conveyed can be sucked from the pump rotor via the intake or suction bell and can be discharged again via the diffusor section, the feed tube and via the outlet stub from the feed column of the pumping apparatus. The diffusor includes an inlet section arranged between an outlet section of the diffusor and the pump rotor, wherein a first part section is formed at the outlet section adjacent to the inlet section, with the first part section being inclined with respect to the diffusor axis at a first predefinable outlet angle in a direction towards the feed tube. In accordance with the invention a second part section adjoining the first part section is formed at the outlet section, with the second part section being inclined with respect to the diffusor axis at a second outlet angle different from the first outlet angle.

It is essential for the invention that a second part section is formed adjoining the first part section at the outlet section of the diffusor, with the second part section being inclined with respect to the diffusor axis at a second outlet angle different from the first outlet angle. In contrast the outlet section in the state of the art was previously only of one part design. This had the effect that fluid entering into the feed tube from the diffusor section would be subjected to a very sudden, this means abrupt transition and/or abrupt change of direction of the flow direction, which led to unnecessary swirling and turbulence in the fluid and therefore finally to energy losses, as was already described in detail in the introduction with reference to the FIG. 1 a and FIG. 1 b.

This negative effect due to swirling and turbulence in the flow direction behind the outlet of the diffusor is substantially suppressed by means of the present invention, since the outlet section of the diffusor in accordance with the invention is divided into at least two part sections which have a different inclination so that the fluid is subjected to a significantly less abrupt transition on the exit from the diffusor into the feed tube, as the space between the diffusor surface and the inner wall of the diffusor section expands in at least two steps on a step by step basis. In other words a less abrupt change of direction of the fluid flow takes place for a diffusor in accordance with the invention, whereby less turbulence arises, therefore less hydraulic losses arise and thus the energy efficiency is significantly improved in contrast to the state of the art. This means that on use of a diffusor in accordance with the invention a higher pump head can be achieved for the same drive energy supplied into the pump and/or less drive energy is required with an electrically driven pump for the same pump head on use of a diffusor in accordance with the invention, this means that less electrical energy is required for the drive of the pump.

A further significant advantage of a diffusor in accordance with the invention is its slender design. As can, for example, already be easily recognized by comparison of a known diffusor in accordance with FIG. 1 a and/or FIG. 1 b with a diffusor in accordance with the invention in accordance with FIG. 2 a or FIG. 2 b, the outlet section of a diffusor in accordance with the invention is significantly more slender and can e.g. also be designed shorter, since the outlet section is generally more inclined with respect to the diffusor axis so that the outlet section approaches the diffusor axis on a shorter distance than for a known diffusor. Due to this, the step remaining at the outlet of the diffusor between the end of the outlet section and the diffusor axis can also be achieved with a shorter construction length of the diffusor. Alternatively, or at the same time, also a smaller step can be achieved for a shorter construction length of the diffusor in comparison to the state of the art. Since the diffusor in accordance with the invention has less mass and is therefore lighter, than a diffusor known from the state of the art, the attachment means by means of which the diffusor is attached at the inner wall of the diffusor section can also be of less massive design, whereby material can be saved again in turn.

All this saves material as the person of ordinary skill in the art understands without further ado, reduces the weight of the diffusor, and also reduces the friction losses and flow losses within the diffusor for a reduced construction length of the diffusor and therefore finally saves cost not only on operation of the diffusor, but also on manufacture of the diffusor, whereby the price of a diffusor in accordance with the invention and/or the price of a pump having a diffusor in accordance with the invention can be reduced and therefore the competitiveness of this product is increased by means of the invention.

For a preferred embodiment of a pumping apparatus in accordance with the invention at least one further third part section is additionally arranged at the outlet section, with the third part section being inclined with respect to the diffusor axis at a third outlet angle, wherein the third outlet angle is preferably, but not necessarily different from the first outlet angle and/or different from the second outlet angle.

In this connection the second outlet angle measured with respect to the diffusor axis is very advantageously larger than the first outlet angle measured with respect to the first diffusor axis in practice, whereby a particularly gentle transition of the fluid from the diffusor into the feed tube is ensured, since the distance between the outlet section of the diffusor and the inner wall of the diffusor section increases step by step in the direction towards the feed tube. As investigations by the inventors have shown the first outlet angle advantageously amounts to at most 15 degrees, preferably lies in the range of between 6 degrees to 12 degrees and in particular lies at 12 degrees, while the second outlet angle preferably amounts to at most 30 degrees, advantageously lies in the range of between 12 degrees and 24 degrees and in particular lies at 18 degrees. In this connection, a difference angle between the first outlet angle and the second outlet angle is selected in the range of between 6 degrees to 12 degrees in practice, and is preferably selected at 8 degrees in practice.

The third part section can advantageously be formed between the first part section and the second part section at the outlet section, wherein preferably, but not necessarily, the third outlet angle is larger than the first outlet angle and smaller than the second outlet angle.

For an embodiment particularly important in practice the first part section and/or the second part section and/or the third part section are in the form of a straight cone and/or of a straight truncated cone, this means that the first outlet angle is constant in the region of the overall first part section and/or the second outlet angle is constant in the region of the overall second part section and/or the third outlet angle is constant in the region of the overall third part section.

It is naturally understood that a pumping apparatus in accordance with the invention can be a one-stage pumping apparatus, but also a multi-stage pumping apparatus having a plurality of pump rotors arranged in series with respect to the diffusor axis, wherein preferably two pump rotors arranged in series can be provided.

In this connection a pumping apparatus in accordance with the invention is frequently a vertical pump, in particular a vertical pump for the conveyance of water, waste water or for the conveyance of another liquid fluid in practice.

In this connection the invention moreover relates to a diffusor as such, as is described in the framework of this application together with a pump and can, in particular also be configured as a retrofitting part and/or a replacement part, so that existing older pumps can also be retrofit with a diffusor in accordance with the invention, so that also the efficiency of older pumps can be increased and/or improved retrospectively by the invention.

In the following the invention will be described in detail with reference to the drawing. There is shown in schematic illustration:

FIG. 1 a a vertical pump having a diffusor known from the state of the art;

FIG. 1 b the diffusor of FIG. 1 a in a more detailed illustration;

FIG. 2 a a pumping apparatus in accordance with the invention having two part sections at the outlet of the diffusor partially in section;

FIG. 2 b the diffusor of FIG. 2 a in a more detailed illustration.

The FIG. 1 a and/or FIG. 1 b relate to a vertical pump known and in use for a long time for a better understanding and for a delimitation of the invention with respect to the state of the art, with the vertical pump already having been described in detail in the introduction and for this reason no longer having to be discussed further at this point.

With reference to FIG. 2 a and FIG. 2 b a particularly preferred embodiment of a pumping apparatus in accordance with the invention will be explained in the following by way of example, the pumping apparatus specifically being a vertical pump for the conveyance of large amounts of water and at relatively small feed heights in this example. In FIG. 1 a, the vertical pump in accordance with the invention, which will be referred to in the following totally with the reference numeral 1, is shown only partially in section in the region where the diffusor is provided in the feed column for reasons of clarity. FIG. 2 b shows an illustration true to detail for a better understanding of the diffusor of FIG. 2 a.

The vertical pump 1 in accordance with the invention in accordance with FIG. 2 a and/or FIG. 2 b includes a feed column 2 having a rotor housing 3 extending about a diffusor axis A of the vertical pump 1, with the feed column being arranged between an intake, not shown for reasons of clarity, and a diffusor 5 provided in a diffusor section 4, as well as having a feed tube 6 adjoining at the diffusor section 4 and having a likewise non-illustrated outlet stub of the vertical pump 1. In this connection a pump rotor 7 is arranged in the rotor housing 3 such that, in the operating state, a fluid F to be conveyed from the pump rotor 7 can be sucked via the intake and can be discharged again by the diffusor section 4, the feed tube 6 and via the outlet stub of the feed column 2 of the vertical pump 1. The diffusor 5 includes an inlet section 51 arranged between an outlet section 52 of the diffusor 5 and the pump rotor 7, with a first part section 521 being formed adjoining the inlet section 51 at the outlet section 52, and the first part section being inclined with respect to the diffusor axis A at a first predefined outlet angle α in a direction towards the feed tube 6. In accordance with the invention a second part section 522 is formed at the outlet section 52 adjoining the first part section 521, with the second part section being inclined with respect to the diffusor axis A at a second outlet angle β different from the first outlet angle α.

In this connection the pump rotor 7 is driven by a, for reasons of clarity, non-illustrated motor arranged downstream via a drive shaft likewise not shown. Within the diffusor 5, which does not rotate with the pump rotor 7, but is statically connected to an inner wall of the diffusor section 4 by means of attachment means 9, for example, by means of diffusor vanes, the drive shaft is stored in bearings 10 settable with respect to the diffusor axis A.

Thus the vertical pump 1 in accordance with FIG. 2 a and/or FIG. 2 b substantially differs from the vertical pump 1′ known from the state of the art in accordance with FIG. 1 a and/or FIG. 1 b in that a diffusor 5 in accordance with the invention is installed in the vertical pump of FIG. 2 a and/or FIG. 2 b. Apart from the diffusor 5 in accordance with the invention the vertical pump in accordance with FIG. 2 a and/or FIG. 2 b is thus substantially equal in construction to the vertical pump 1′ in accordance with FIG. 1 a and/or FIG. 1 b known from the state of the art.

Very particularly preferably the second outlet angle β measured with respect to the diffusor axis A is larger than the first outlet angle α measured with respect to the diffusor axis A in practice, as can clearly be seen in the FIG. 2 a and/or FIG. 2 b. In the present specific embodiment the first outlet angle α corresponds to approximately 10 degrees and the second outlet angle β amounts to approximately 18 degrees, so that the difference angle between the first outlet angle α and the second outlet angle β lies at approximately 8 degrees. In this connection the first outlet angle α is constant in the region of the overall first part section 521 and the second outlet angle β is constant in the region of the overall second part section 522. This means that the outer shape of the first part section 521 and of the part section 522 corresponds to a straight conical section and/or to a straight truncated cone.

For a better understanding a thought line L′ is shown in FIG. 2 b which by way of comparison emphasizes the extent of the outlet section 52′ which in accordance with FIG. 1 a and/or FIG. 1 b is formed in the shape of a single truncated cone having an angle of inclination α₁′ as is known for a diffusor 5′ known from the state of the art.

It can very clearly be seen that the outlet section 52 of the diffusor 5 is significantly more strongly inclined with respect to the diffusor axis A by means of the additional second part section 522 adjoining the first part section 521, with the second part section 522 extending at a larger angle of inclination β with respect to the diffusor axis A, which stronger inclination has the effect that fluid F flowing from the diffusor section 4 into the feed tube 6 is subjected to a very gentle transition and/or change of direction of the flow direction, this means a very less sudden or abrupt transition and/or abrupt change of direction of the flow direction, so that the unnecessary swirls and turbulence in the fluid F known from the state of the art can be very strongly suppressed which has the effect that unnecessary energy losses can be avoided and the overall efficiency of the pump is increased on use of a diffusor 5 in accordance with the invention.

This means that the negative effect known from the state of the art due to swirls and turbulence in the flow direction behind the outlet of the diffusor known from the state of the art is substantially suppressed by means of the present invention, since the outlet section 52 of the diffusor 5 in accordance with the invention is divided into at least two part sections 521, 522 which have a different and overall stronger inclination than for a diffusor known from the state of the art, so that the fluid F is subjected to a significantly less abrupt transition on the exit from the diffusor 5 in accordance with the invention into the feed tube, since the space between diffusor surface and the inner wall of the diffusor section 4 is expanded stronger step by step in at least two steps and generally over a shorter distance. In other words, for a diffusor 5 in accordance with the invention a less abrupt change of direction of the fluid flow takes place, in particular at the diffusor outlet, whereby less turbulence arises, and therefore less hydraulic losses arise and thus the energy efficiency is significantly improved in comparison to the state of the art.

It has to be understood that all embodiments of the invention described in the framework of this application are to be understood only by way of example and/or exemplary and that the invention encompasses, in particular, but not only, all suitable combinations of the described embodiments just like simple advances which the person of ordinary skill in the art identifies without further ado due to his practical experience. 

1. A pumping apparatus including a feed column (2) extending around a diffusor axis (A) of the pumping apparatus and having a rotor housing (3) which is arranged between an intake and a diffusor (5) arranged in a diffusor section (4), as well as having a feed tube (6) with an outlet stub and adjoining the diffusor section (4), wherein a pump rotor (7) is arranged in the rotor housing (3) such that, in an operating state, a fluid (F) to be conveyed can be sucked by the pump rotor (7) via the intake, and can be discharged again from the feed column (2) of the pumping apparatus via the diffusor section (4), the feed tube (6) and via the outlet stub, wherein the diffusor (5) includes an inlet section (51) arranged between an outlet section (52) of the diffusor (5) and the pump rotor (7) and a first part section (521) adjacent to the inlet section (51) is formed at the outlet section (52), with the first part section being inclined with respect to the diffusor axis (A) at a first predefinable outlet angle (α) in a direction towards the feed tube (6), characterized in that a second part section (522) adjoining the first part section (521) is formed at the outlet section (52), with the second part section being inclined with respect to the diffusor axis (A) at a second outlet angle (β) different from the first outlet angle (α).
 2. The pumping apparatus in accordance with claim 1, wherein at least one third part section is formed at the outlet section (52), with the third part section being inclined with respect to the diffusor axis (A) at a third outlet angle, wherein the third outlet angle is preferably different from the first outlet angle (α) and/or different from the second outlet angle (β).
 3. The pumping apparatus in accordance with claim 1, wherein the second outlet angle (β) measured with respect to the diffusor axis (A) is larger than the first outlet angle (α) measured with respect of the diffusor axis (A).
 4. The pumping apparatus in accordance with claim 1, wherein the first outlet angle (α) amounts to at most 15 degrees, preferably lies in a range of from 6 degrees to 12 degrees and in particular lies at 10 degrees and/or wherein the second outlet angle (β) amounts to at most 30 degrees, preferably lies in a range of from 12 degrees to 24 degrees and in particular lies at 18 degrees.
 5. The pumping apparatus in accordance with claim 1, wherein a difference angle between the first outlet angle (α) and the second outlet angle (β) lies in the range from 6 degrees to 12 degrees, preferably lies at 8 degrees.
 6. The pumping apparatus in accordance with claim 2, wherein the third part section is formed at the outlet section (52) between the first part section (521) and the second part section (522); and the third outlet angle is preferably larger than the first outlet angle (α) and smaller than the second outlet angle (β).
 7. The pumping apparatus in accordance with claim 1, wherein the first outlet angle (α) is constant in the region of the overall first part section (521) and/or the second outlet angle (β) is constant in the region of the overall second part section (522) and/or the third outlet angle is constant in the region of the overall third part section.
 8. The pumping apparatus in accordance with claim 1, wherein the pumping apparatus includes a multi-stage pumping apparatus having a plurality of pump rotors (7) arranged in series with respect to the diffusor axis (A) and preferably includes two pump rotors (7) arranged in series.
 9. The pumping apparatus in accordance with claim 1, wherein the pumping apparatus is a vertical pump, in particular a vertical pump for the conveyance of water, waste water or for the conveyance of a different liquid fluid.
 10. A diffusor for a pumping apparatus (1), wherein the diffusor includes an outlet section (52) and an inlet section (51), and a first part section (521) adjacent to the inlet section (51) is formed at the outlet section (52), with the first part section being inclined with respect to the diffusor axis (A) at a first predefinable outlet angle (α), characterized in that a second part section (522) adjoining the first part section (521) is formed at the outlet section (52), with the second part section being inclined with respect to the diffusor axis (A) at a second outlet angle (β) different from the first outlet angle (α),
 11. The diffusor in accordance with claim 10, wherein at least one third part section is formed at the outlet section (52), with the third part section being inclined with respect to the diffusor axis (A) at a third outlet angle, wherein the third outlet angle is preferably different from the first outlet angle (α) and/or different from the second outlet angle (β).
 12. The diffusor in accordance with claim 10, wherein the second outlet angle (β) measured with respect to the diffusor axis (A) is larger than the first outlet angle (α) measured with respect to the diffusor axis (A).
 13. The diffusor in accordance with claim 10, wherein the first outlet angle (α) amounts to at most 15 degrees, preferably lies in the range of 6 degrees to 12 degrees, and in particular lies at 10 degrees; and/or wherein the second outlet angle (β) amounts to at most 30 degrees, preferably lies in a range of between 12 degrees and 24 degrees, and in particular lies at 18°; and/or wherein a difference angle between the first outlet angle (α) and the second outlet angle (β) lies in the range of from 6 degrees to 12 degrees and preferably lies at 8 degrees.
 14. The diffusor in accordance with claim 8, wherein the third part section is formed at the outlet section (52) between the first part section (521) and the second part section (522), and the third outlet angle is preferably larger than the first outlet angle (α) and smaller than the second outlet angle (β).
 15. The diffusor in accordance with claim 8, wherein the first outlet angle (α) is constant in the region of the overall first part section (521) and/or the second outlet angle (β) is constant in the region of the overall second part section (522) and/or the third outlet angle is constant in the region of the overall third part section. 